Epidemiological survey of tick bites occurring in Hyogo Prefecture from 2014 through 2018

Abstract

: The present report summarizes 519 cases of tick bites in Hyogo Prefecture over 5 years from 2014 through 2018. There were 222 male and 297 female cases, and ages ranged from 0 to 95 years old. The most common age group was the 70 to 79 age range ( n = 124). Tick bites were especially frequent in May, June, and July. The causative ticks in 431 tick bite cases were identified as Amblyomma testudinarium (AT), followed by 72 cases involving Haemaphysalis longicornis ticks, and 7 cases involving Haemaphysalis hystricis ticks. Among the 431 AT bites, 61 cases developed erythema larger than 50 mm in diameter at the bite site, and those patients were diagnosed with tick-associated rash illness (TARI). Although tick-borne diseases such as severe fever with thrombocytopenia syndrome (SFTS) and Japanese spotted fever (JSF) that are related to the above-mentioned tick species were reported in Hyogo Prefecture, there were no patients who presented with such diseases in the current report. Our findings suggest that SFTS or JSF infections that develop after tick bites are most likely accidental occurrences and that dermatologists in western Japan should pay attention to TARI as a differential diagnosis of Lyme disease in tick bite cases.